This invention relates to an apparatus and method for automatically inspecting electrical connector pins and in particular to an apparatus and method for automatically inspecting electrical connector pins for a dual inline printout electrical connector package.
The use of electrical connectors with parallel rows of pins is common in electronic interconnections such as those encountered in the manufacture and assembly of semiconductor components. Connector failures are a major cause of electrical system failures and are a major obstacle in the automation of the assembly of electronic components onto printed circuit cards or other types of assemblies.
In the semiconductor industry, electronic integrated circuits and connectors commonly use metal interconnection pins arranged in parallel rows. A common failure mode is the bending, deformation, breaking and contamination of these pins. When a unit with defective pins is assembled into a larger electronic system, it causes the larger system to fail which results in an expensive repair due to the difficulty in tracking down the defective component and replacing it. Even slightly bent pins can cause catastrophic failures. Clearly, it is better to detect and correct defective pins before they create bigger problems. Manual inspection of components and their pins has been found to be extremely tedious. Fatigue severely limits human effectiveness in making manual inspection expensive and unreliable. There is a clear need for automatic pin inspection.
An automated lead inspection system is commercially available from Synterception Incorporated, 59 El Pueblo Rd., Scotts Valley, Calif. 95066 and from Adcotech Corporation, 575 Modcourt, Sunnyvale, Calif. 54086. The precision inspection problem has been identified and discussed in publications such as the IEEE Computer Magazines, Vol. 13, No. 5, May 1980; and Vol. 15, No. 12, December 1982. However, none of the above referenced systems can detect pin presence where no missing leads are present, the straightness of pins where the pins are not bent past predetermined limits, the lengths of pins where pins are too short or too long and the overall dimensions of the pins where the diameter is within tolerance.